I've always insisted on an OEM screen and had no trouble other than having to be a little firm when dealing with my insurers about it, had OEM screens on cars older than 3 years too so stick to your guns if you want a genuine screen
Also, question the fitters beforehand about the removal method of the old screen, there is a particular method and tooling required for the mk5 and other cars with a bonded windscreen (cheese wire type affair with a ratchet mechanism that suckers to the inside of the screen),
Autoglass in my case first denied the existence of such a method but backed down after admitting they just didn't have a trained fitter for it lol! One 'master fitter' later and some blowing of dust of the correct equipment they did a spot on job as they did subsequent times on the same car a year later and the next car after that...
I'm known at the local branch as the 'picky bloke' with the nice car, but I hate shoddy jobs in general never mind on the car
Just to note, when they did my last screen (with the correct removal method) the fitter openly admitted that it was a pain to use and took longer and seemed quite proud about telling me how his next job was another mk5 golf albeit a lease car and he was just going to cut the screen out the quick way...